Conventional restraint belt systems employ a belt buckle or belt retractor which is positioned inboard the occupant seating position to mount the inboard end of a occupant restraint belt.
It has been proposed that the inboard belt end be mounted on the vehicle seat so as to move with the seat during fore and aft seat adjustment. It has been recognized that such a direct mounting of the restraint belt end on the seat has the disadvantage of requiring that the seat adjusting mechanism be strong enough to maintain the seat against movement by the occupant restraint loads imposed on the belt. Accordingly, prior patents such as Dorn U.S. Pat. No. 3,606,454, issued Aug. 21, 1969, and Magyar U.S. Pat. No. 4,109,962, issued Aug. 29, 1978, have proposed that an anchor strap separate from the restraint belt have one end mounted on the vehicle floor rearward the seat and the other end mounted on the seat frame. A spring wound retractor reel provides the mounting of one of the anchor belt ends and is selectively locked to anchor the seat against forward movement by the occupant restraint load.
Conventional passive restraint belt systems have an outboard belt end connected to the vehicle door and an inboard end mounted by a retractor so that opening and closing movement of the door automatically moves the restraint belt between the restraining and non-restraining positions. The restraint belt retractor is preferably of the vehicle inertia sensitive type having a pendulum or the like which automatically fixes the length of the restraint belt in response to a predetermined change in vehicle velocity or attitude. It is characteristic of vehicle inertia sensitive retractors that the retractor must be mounted at a predetermined fixed attitude in the vehicle so that the pendulum always hangs vertically to lock the retractor at a consistency predictable level of change of vehicle velocity or attitude. The forward and rearward tilting movement of a vehicle seat undesirably influences the performance of the inertia locking seat belt retractor and accordingly prevents the mounting of such a retractor on the seat.
The present invention provides a new and improved seat belt anchorage system by which the vehicle inertia sensitive locking restraint belt retractor may be mounted for adjusting fore and aft adjusting movement with a vehicle bench seat which tilts as well as moving fore and aft.